The invention relates generally to electrodes for medical applications, and more specifically to a method of manufacturing such an electrode with different geometries, specifically hollow bodies.
Electrodes made of carbon lend themselves particularly well to use in medicine since carbon is a material that is readily tolerated by the human body, i.e. it is body compatible. Of the known carbonaceous materials, pyrocarbon or pyrographite, and glassy carbon enjoy the widest use. For example, German patents 26 13 052 and 26 13 072 disclose such use. This is due especially to the fact that these materials can be activated, that is, they permit the surface of the electrode to be enlarged.
The shape of the electrodes or electrode heads made from the aforesaid carbonaceous materials has up to now been limited largely to a mushroom shape, that is, to a hemispherical geometry. However, full spheres occasionally are also used as electrode tips with these so-called tip electrodes. The reason for these particular geometries is that it is very difficult in practice to realize other electrode shapes, such as tubular shapes or hollow bodies, with these materials. In fact, up to now it has only been possible to produce single electrodes with other geometries on a laboratory scale.
Since suitable carbon electrodes are not currently available for important applications, particularly the bipolar stimulation of the heart, where tubular electrodes are predominantly required, other electrode materials, such as platinum, must be resorted to in such cases. However, this means that different materials have to be used for the two electrodes required with pacemakers, that is, the stimulating electrode and the indifferent electrode. This is undesirable. Besides, in certain fields of application, such as in the case of implantable oxygen sensors, platinum cannot be used.
The present invention is directed to overcoming the problem of developing a method for manufacturing electrodes for medical applications with different geometries, and more particularly as hollow bodies.